Artur Mas, president of Catalonia. His party is not tipped to win enough seats to force a vote on secession in Sunday's election. Photograph: Jaume Sellart/EPA

It's always tempting to look for straightforward explanations for complex phenomena. The latest example is the rise of secessionist parties in several European countries, notably Belgium (Flanders), the UK (Scotland) and Spain, where this weekend Catalonia is holding regional elections, the outcome of which could pave the path towards independence. Most commentators tend to explain it primarily by economic factors. A more careful analysis would suggest that a number of other factors are at play. While the economic crisis has undoubtedly exacerbated matters in some cases, especially in Catalonia, it is far from being the most important factor explaining why secessionist parties are in the ascendancy.

The first element to appreciate is that these parties all operate in regions with a longstanding identity as distinct nations within their respective states. Walker Connor, the prominent American scholar of nationalism, showed long ago that regional nationalism is never primarily economic in character. This is because economic imbalances deepen tensions between communities but do not define the identity of such communities. Economic disparities in Germany and Italy, for instance, are as great as, if not greater than, those in either Belgium, Spain or the UK, yet no rise in support for secessionist parties has taken place. The case of Italy is particularly instructive. The Northern League's attempt to forge a separate national identity for Northern Italy out of little more than economic grievances has failed spectacularly, and the outcome of next year's general election will likely not be kind to the party. Meanwhile, the government in Rome, the most "northern" in decades, is spearheading a degree of "recentralisation".

Specific factors, unrelated to the economic crisis, have played an important role in each of these cases. In the Basque Country, a turning point was the effective demise of Eta, which made possible the unification of the leftwing secessionist forces under the banner of Euskal Herria Bildu. In Catalonia, the ruling CiU party federation has been seeking a new financial settlement with Madrid since the early 1990s, and it was the curtailment of the region's new statute of autonomy by the Constitutional Tribunal in 2010 that fuelled secessionism.

As for Flanders and Scotland, the fact that the nationalist parties are led by charismatic politicians with a strong personal following, Bart de Wever and Alex Salmond, respectively, has made secessionism appear more popular than it actually is.

Beyond these particular conditions, there are also shared longer-term factors at play. The first is the enduring appeal of the notion of sovereignty. In spite of having been repeatedly pronounced dead, sovereignty is in fact still an attribute that makes a substantial difference to national communities' ability to govern themselves in today's – supposedly "post-sovereign" – world and explains why those who do not possess it are powerfully motivated to acquire it.

Second, and relatedly, federal and quasi-federal structures have clear limitations. The autonomy enjoyed by stateless nations within a federal system can only go so far and will always remain a second best in the eyes of many. Once the transformation of the state from a unitary to a federal or quasi-federal order is completed, as in Belgium, Spain and the UK, the question of independence is bound to arise sooner or later.

Last, the EU context is a facilitating condition. Uncertainty over the legal framework governing the creation of new states within the EU allows secessionist parties to play the European card with a considerable degree of credibility, while state-wide parties have largely failed to exploit the European dimension to their advantage.

The growing popularity of secession is thus not primarily a product of the economic crisis. It has deeper and more complex roots and will not go away when the economy recovers. Although, in all these cases, the mass public is considerably less supportive of secession than the nationalist parties, it would be a mistake for both the state governments concerned and the EU to simply dismiss it or wish it away. The primacy traditionally given to raison d'etat (national interest) and the stability of international borders should give way to a more constructive response to the aspirations of many in Europe's stateless nations.

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